A geometry for optimizing nanoscale magnetic resonance force microscopy

TL;DR

This paper introduces a novel experimental geometry for magnetic resonance force microscopy (MRFM) that enhances sensitivity and applicability to challenging samples at the nanoscale.

Contribution

The authors implement a new MRFM geometry with the cantilever axis normal to the magnetic field and RF source, enabling improved measurements of nuclear spins at the nanoscale.

Findings

Achieved high magnetic field gradients (>10^5 T/m) within 100 nm of the magnetic tip.

Measured statistical polarization of hydrogen in polystyrene with negligible dissipation.

Demonstrated rotating RF magnetic fields over 12 mT at 115 MHz.

Abstract

We implement magnetic resonance force microscopy (MRFM) in an experimental geometry, where the long axis of the cantilever is normal to both the external magnetic field and the RF microwire source. Measurements are made of the statistical polarization of $^1$H in polystyrene with negligible magnetic dissipation, gradients greater than $10^5$ T/m within 100 nm of the magnetic tip, and rotating RF magnetic fields over 12 mT at 115 MHz. This geometry could facilitate the application of nanometer-scale MRFM to nuclear species with low gyro-magnetic ratios and samples with broadened resonances, such as In spins in quantum dots.